CMFCRibbonColorButton* pRootColorBtn = DYNAMIC_DOWNCAST( CMFCRibbonColorButton, pRibbonBar->FindByID(ID_DUPLICATE_ROOT_COLOR));
pRootColorBtn->SetToolTipText( "Selection of Color for Root File of Duplicate Files");
strText = "\n\nClick on this Button to Select the Color of the Duplicate Root File. ";
strText += "\n\nA Duplicate Root File is the First File of a List of Files that will be renamed with the same name.";
strText += "\nThis happens when the Renaming Mask is poorly discriminant or when pictures are taken in Burst Mode.";
pRootColorBtn->SetDescription( strText);

I would like to change the size of the tooltip rectangle, so that the width is inscreased (I do not like the default width ...)